Fitting TRV whilst boiler swap takes place

[Fred]

I would like to fit a few TRV myself whilst the plumber fits a new boiler - obviously not when he is flushing the system 8-))) - I presume that he disconnects the old boiler, drains the system and starts to work on the boiler. I know that I could ask him to do it, but not only have I always wanted to try my luck with this, I am also keen to make savings wherever I reasonably can. A TRV from B&Q is only a fraction of the cost that he would charge me for the fitting. Needless to say I am not keen on messing up his job, or getting myself into trouble re boiler fitting and whatnot. In an ideal world, I would do this myself with the plumber unaware of what I am up to. Is that makeable, and if so, how to best do it.

Fred

[Set Square]

You can't hope to do this without telling the person installing the boiler - for several reasons. Firstly, it will probably take you longer to fit the TRVs than it will take him to fit the boiler. Secondly, you are *saving* him some work - so you might be able to negotiate a price reduction. As part of the of the boiler installation, the system will need to be flushed. You can do a significant part of this yourself. In order to fit new valves, you will have to drain the rads and take them off the wall. While you are doing this, take them outside and give them a thorough cleaning out with a hose pipe. This is far more effective than anything the plumber will do, left to his own devices.

While you're at it, fit new lockshield valves as well - preferably with built-in drain points, to make life easier in future. [If your boiler change is taking you from a vented to a sealed system, this is all the more reason for changing the lockshields - 'cos the old ones will probably leak under pressure, anyway.]

Also, while you're at it, fit good quality TRVs and lockshields - otherwise you'll be doing it all again in a couple of years. I'm sure someone will be along with recommendations for make and model of valve.

[EricP]

Removing the old TRV is easy, but the problem may be matching the pipework up quickly to reconnect.

Some TRV's have a slider on the radiator tail so you can slide the valve along a few cm. You should get one of those, it may make it easier to quickly reassemble.

As he is there, it would probably be far more economical to get him to do it.

Also the quality of the replacements are questionable. I was faced with this last week. I was going around Wickes and seeing bins full of TRV heads at £5, and opted for a much more expensive decent make.

[Ben Blaukopf]

That's exactly what I did. But I did it the week before my plumber fitted the boiler. Two of my radiators had rounded bleed valves, so I drilled an airhole in order to drain the water, and then put new radiators in. I had to move the pipes on all but one radiator, as the new valves had substantially longer tails.

Needless to say this all took rather longer than the plumber took with the boiler, so it's just as well I did it beforehand. My plumber insisted that all the rads had to have TRVs, so obviously he knew full well I was doing that bit myself.

If your old valves are the type that take a special radiator spanner (basically a big allen key, can be bought anywhere) then be warned then you will end up hitting the spanner with a hammer to get the valves off. This is noisy :) I did it on fireworks night, though you've missed that one!

Ben

[Set Square]

I have a length of iron pipe which I slide over the Allen key to increase the leverage by a factor of about 6. No need for any violence, then!

[logized]

I have recently fitted a new CH system and I did some web research before choosing the TRVs because just getting cheap ones can be a false economy. I found the Drayton TRV4 to be well regarded and those made by Pegler were a bit cheaper and fairly good too. I decided on the Drayton - (they looked better). B&Q sell them, but I got a much better price at the plumbers merchant - your plumber can probably get them even cheaper. You should fit the TRVs on all rads but the one that is in the room where the room thermostat is fitted - this ensures that the thermostat can shut-off the boiler to save energy and comply with building regs.

Dave

[Malc]

You could drain the system down before he starts work. Do it a day early and have loads of time to fit the TRVs.

-- Malc

[Kalico]

How long could you leave a system drained down for, without corrosion of the inside of old radiators becoming an issue?

Maybe it is not an issue. I would like to remove our old boiler that is being replaced in advance of the plumber coming to fit the new one. However, the plumber may be a week away.

TIA Rob

Replace 'spam' with 'org' to reply

[Set Square]

It's not really an issue.

You're going to remove the rads and wash them out anyway (aren't you?!) prior to fitting the TRVs. If you're worried about corrosion during the week or so in which they're not in use, drain them well after washing out, and dry the insides by blowing air through with a vacuum cleaner.

[Andrew Gabriel]

Part of installing a new boiler is to flush all the sluge out of the system, which is best done with the old boiler. If you are going to remove the old boiler, talk with your plumber as he may require you to perform this task before removing the old boiler.

[Kalico]

Well I ran some cleanser/sludge remover through the system a few months back so there really shouldn't be that much in there.

Certainly the water was running nice and clean after a number of fills and drains.

I then finally filled it with an inhibitor additive.

I was not planning to take every rad off to flush through though I realise this is an ideal thing to do. Nor was I going to put TRVs on the rads.

The only reason I want to remove the old boiler myself is that I am likely to make less mess than the plumber, since I can take more time and be more careful. The old boiler had a fire in it after soot built up and even when the plumber checked it to pronounce it dead there was soot all over the house for days.

Rob

Replace 'spam' with 'org' to reply